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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Molecular Characterisation and Prognostic Biomarker Discovery in Human Non-Small Cell Lung Cancer

Edlund, Karolina January 2012 (has links)
Non-small cell lung cancer (NSCLC) constitutes a clinically, histologically, and genetically heterogeneous disease entity that represents a major cause of cancer-related death. Early-stage patients, who undergo surgery with curative intent, experience high recurrence rates and the effect of adjuvant treatment is modest. Prognostic biomarkers would be of particular relevance to guide intensified treatment depending on expected outcome and moreover often infer a biological role in tumourigenesis. This thesis presents a translational study approach to establish a well-characterised NSCLC frozen-tissue cohort and to obtain a profile of each specimen with regard to genome-wide copy number alterations, global gene expression levels and somatic mutations in selected cancer-related genes. Furthermore, the generation of a formalin-fixed, paraffin-embedded tissue microarray enabled validation of findings on the protein level using immunohistochemistry. The comprehensive molecular characterisation, combined with data on clinical parameters, enabled the analysis of biomarkers linked to disease outcome. In Paper I, single nucleotide polymorphism arrays were applied to assess copy number alterations in NSCLC and associations with overall survival in adenocarcinoma and squamous cell carcinoma were described. In Paper II, we evaluated expression levels of selected stromal proteins in NSCLC using immunohistochemistry and the adhesion molecule CD99 was identified as an outcome-related biomarker in two independent cohorts. Paper III presents a strategy for prognostic biomarker discovery based on gene expression profiling, meta-analysis, and validation of protein expression on tissue microarrays, and suggests the putative tumour suppressor CADM1 as a candidate biomarker. In Paper IV, we propose a prognostic role for tumour-infiltrating IGKC-expressing plasma cells in the local tumour microenvironment, indicating an involvement of the humoral immune response in anti-tumor activity. In Paper V, we combined next-generation deep sequencing with statistical analysis of the TP53 database to define novel parameters for database curation. In summary, this thesis exemplifies the benefits of a translational study approach, based on a comprehensive tumour characterisation, and describes molecular markers associated with clinical outcome in NSCLC.
42

Bayesian Hidden Markov Models for finding DNA Copy Number Changes from SNP Genotyping Arrays

Kowgier, Matthew 31 August 2012 (has links)
DNA copy number variations (CNVs), which involve the deletion or duplication of subchromosomal segments of the genome, have become a focus of genetics research. This dissertation develops Bayesian HMMs for finding CNVs from single nucleotide polymorphism (SNP) arrays. A Bayesian framework to reconstruct the DNA copy number sequence from the observed sequence of SNP array measurements is proposed. A Markov chain Monte Carlo (MCMC) algorithm, with a forward-backward stochastic algorithm for sampling DNA copy number sequences, is developed for estimating model parameters. Numerous versions of Bayesian HMMs are explored, including a discrete-time model and different models for the instantaneous transition rates of change among copy number states of a continuous-time HMM. The most general model proposed makes no restrictions and assumes the rate of transition depends on the current state, whereas the nested model fixes some of these rates by assuming that the rate of transition is independent of the current state. Each model is assessed using a subset of the HapMap data. More general parameterizations of the transition intensity matrix of the continuous-time Markov process produced more accurate inference with respect to the length of CNV regions. The observed SNP array measurements are assumed to be stochastic with distribution determined by the underlying DNA copy number. Copy-number-specific distributions, including a non-symmetric distribution for the 0-copy state (homozygous deletions) and mixture distributions for 2-copy state (normal), are developed and shown to be more appropriate than existing implementations which lead to biologically implausible results. Compared to existing HMMs for SNP array data, this approach is more flexible in that model parameters are estimated from the data rather than set to a priori values. Measures of uncertainty, computed as simulation-based probabilities, can be determined for putative CNVs detected by the HMM. Finally, the dissertation concludes with a discussion of future work, with special attention given to model extensions for multiple sample analysis and family trio data.
43

Bayesian Hidden Markov Models for finding DNA Copy Number Changes from SNP Genotyping Arrays

Kowgier, Matthew 31 August 2012 (has links)
DNA copy number variations (CNVs), which involve the deletion or duplication of subchromosomal segments of the genome, have become a focus of genetics research. This dissertation develops Bayesian HMMs for finding CNVs from single nucleotide polymorphism (SNP) arrays. A Bayesian framework to reconstruct the DNA copy number sequence from the observed sequence of SNP array measurements is proposed. A Markov chain Monte Carlo (MCMC) algorithm, with a forward-backward stochastic algorithm for sampling DNA copy number sequences, is developed for estimating model parameters. Numerous versions of Bayesian HMMs are explored, including a discrete-time model and different models for the instantaneous transition rates of change among copy number states of a continuous-time HMM. The most general model proposed makes no restrictions and assumes the rate of transition depends on the current state, whereas the nested model fixes some of these rates by assuming that the rate of transition is independent of the current state. Each model is assessed using a subset of the HapMap data. More general parameterizations of the transition intensity matrix of the continuous-time Markov process produced more accurate inference with respect to the length of CNV regions. The observed SNP array measurements are assumed to be stochastic with distribution determined by the underlying DNA copy number. Copy-number-specific distributions, including a non-symmetric distribution for the 0-copy state (homozygous deletions) and mixture distributions for 2-copy state (normal), are developed and shown to be more appropriate than existing implementations which lead to biologically implausible results. Compared to existing HMMs for SNP array data, this approach is more flexible in that model parameters are estimated from the data rather than set to a priori values. Measures of uncertainty, computed as simulation-based probabilities, can be determined for putative CNVs detected by the HMM. Finally, the dissertation concludes with a discussion of future work, with special attention given to model extensions for multiple sample analysis and family trio data.
44

The Research of Chinese Advertisement Copy: the approach of Cognitive Psychology

Hsueh, Hui-Wen 05 September 2008 (has links)
In the end of 1978, China started to launch reforms, especially in economy. Thus, the Chinese advertising industry brings the market back; the commercial advertisement rises again. Over twenty years, some advertisement copies have created billions of sales, however, some of the copies was judged without any creativity. This paper primarily concentrates on studying the Chinese advertisement copy. In reviewing the studies of the Chinese advertisement, this paper takes the approach of cognitive psychology as a theoretical framework. In Richard Atkinson and Richard Shiffrin¡¦s view, when the information inputs in one¡¦s eyes it will become a short-term memory which stored in human brain, by repeating the broadcast information, which will also become a long-term memory. Eventually, if consumers touch the products, no matter the brand or the advertisement, their memories will be aroused from their long-term memory. This research concluded that audiences are attracted by the advertisement because of various affective reactions /emotional response. It showed that the advertisement may focus on consumers¡¦ emotional code ¢w cultural code. So the copywriter can input the Chinese traditional culture in an advertisement copy such as piety, decorum and familism, it will arouse Chinese emotional response more easily.
45

Exploring Cancer's Fractured Genomic Landscape: Searching for Cancer Drivers and Vulnerabilities in Somatic Copy Number Alterations

Zack, Travis Ian 21 October 2014 (has links)
Somatic copy number alterations (SCNAs) are a class of alterations that lead to deviations from diploidy in developing and established tumors. A feature that distinguishes SCNAs from other alterations is their genomic footprint. The large genomic footprint of SCNAs in a typical cancer's genome presents both a challenge and an opportunity to find targetable vulnerabilities in cancer. Because a single event affects many genes, it is often challenging to identify the tumorigenic targets of SCNAs. Conversely, events that affect multiple genes may provide specific vulnerabilities through "bystander" genes, in addition to vulnerabilities directly associated with the targets. We approached the goal of understanding how the structure of SCNAs may lead to dependency in two ways. To improve our understanding of how SCNAs promote tumor progression we analyzed the SCNAs in 4934 primary tumors in 11 common cancers collected by the Cancer Genome Atlas (TCGA). The scale of this dataset provided insights into the structure and patterns of SCNA, including purity and ploidy rates across disease, mechanistic forces shaping patterns of SCNA, regions undergoing significantly recurrent SCNAs, and correlations between SCNAs in regions implicated in cancer formation. In a complementary approach, we integrating SCNA data and pooled RNAi screening data involving 11,000 genes across 86 cell lines to find non-driver genes whose partial loss led to increased sensitivity to RNAi suppression. We identified a new set of cancer specific vulnerabilities predicted by loss of non-driver genes, with the most significant gene being PSMC2, an obligate member of the 26S proteasome. Biochemically, we found that PSMC2 is in excess of cellular requirement in diploid cells, but becomes the stoichiometric limiting factor in proteasome formation after partial loss of this gene. In summary, my work improved our understanding of the structure and patterns of SCNA, both informing how cancers develop and predicting novel cancer vulnerabilities. Our characterization of the SCNAs present across 5000 tumors uncovered novel structure in SCNAs and significant regions likely to contain driver genes. Through integrating SCNA data with the results of a functional genetic screen, we also uncovered a new set of vulnerabilities caused by unintended loss of non-driver genes.
46

Difference in copy number variants in peripheral blood and bone marrow detected by SNP-array / Skillnad i copy number variationer i venblod och benmärg detekterat med SNP-array

Mattsson, Anna January 2011 (has links)
No description available.
47

On the Clinical Applicability and Translation of Genetic Discoveries in Schizophrenia

Costain, Gregory 07 January 2014 (has links)
Schizophrenia is a genetically complex neuropsychiatric disease. Myths and uncertainty about aetiology, and concerns about familial recurrence, may contribute to the significant stigma and burden on families. There has recently been concrete progress in understanding individual genetic causes of schizophrenia, which are now known to extend beyond 22q11.2 microdeletions to include other large rare copy number variations. However, there are limited data on issues germane to the translation of these genetic discoveries into clinical practice. The aim of this thesis was to evaluate the contemporary clinical applicability of genetic testing and genetic counselling in schizophrenia. First, general genetic counselling was provided to both adults with schizophrenia without individually relevant genetic test results and their family members. Pre-counselling, there was evidence of widespread misconceptions about schizophrenia aetiology and familial recurrence risks, which were associated with considerable psychological distress. Post-counselling, the myriad significant lasting benefits of genetic counselling included reductions in stigma. The results provided initial evidence of need for, and efficacy of, genetic counselling for schizophrenia. A first ever study was then conducted of the impact of providing a specific aetiological explanation for schizophrenia. Affected individuals and family members were found to value a molecular genetic diagnosis of a 22q11.2 microdeletion for its ability to explain the presence of stigmatized neuropsychiatric conditions. An investigation of transmission patterns and reproductive fitness associated with 22q11.2 microdeletions provided novel insights into the evolutionary biology and clinical correlates of this structural rearrangement. The results demonstrated the scientific and clinical benefits of identifying a genetic subtype of schizophrenia. Last, high resolution genome-wide microarrays were used to investigate rare copy number variations in a prospectively recruited community-based schizophrenia cohort. Clinically significant variants were greatly enriched in schizophrenia, even with 22q11.2 microdeletions a priori excluded. The collective prevalence of these genetic variants in a single community catchment area was high, approaching that seen in autism, where clinical microarray testing is now a first-tier diagnostic test. Collectively, the findings of these pioneering studies suggest a role for genetic testing and genetic counselling in the contemporary management of schizophrenia.
48

On the Clinical Applicability and Translation of Genetic Discoveries in Schizophrenia

Costain, Gregory 07 January 2014 (has links)
Schizophrenia is a genetically complex neuropsychiatric disease. Myths and uncertainty about aetiology, and concerns about familial recurrence, may contribute to the significant stigma and burden on families. There has recently been concrete progress in understanding individual genetic causes of schizophrenia, which are now known to extend beyond 22q11.2 microdeletions to include other large rare copy number variations. However, there are limited data on issues germane to the translation of these genetic discoveries into clinical practice. The aim of this thesis was to evaluate the contemporary clinical applicability of genetic testing and genetic counselling in schizophrenia. First, general genetic counselling was provided to both adults with schizophrenia without individually relevant genetic test results and their family members. Pre-counselling, there was evidence of widespread misconceptions about schizophrenia aetiology and familial recurrence risks, which were associated with considerable psychological distress. Post-counselling, the myriad significant lasting benefits of genetic counselling included reductions in stigma. The results provided initial evidence of need for, and efficacy of, genetic counselling for schizophrenia. A first ever study was then conducted of the impact of providing a specific aetiological explanation for schizophrenia. Affected individuals and family members were found to value a molecular genetic diagnosis of a 22q11.2 microdeletion for its ability to explain the presence of stigmatized neuropsychiatric conditions. An investigation of transmission patterns and reproductive fitness associated with 22q11.2 microdeletions provided novel insights into the evolutionary biology and clinical correlates of this structural rearrangement. The results demonstrated the scientific and clinical benefits of identifying a genetic subtype of schizophrenia. Last, high resolution genome-wide microarrays were used to investigate rare copy number variations in a prospectively recruited community-based schizophrenia cohort. Clinically significant variants were greatly enriched in schizophrenia, even with 22q11.2 microdeletions a priori excluded. The collective prevalence of these genetic variants in a single community catchment area was high, approaching that seen in autism, where clinical microarray testing is now a first-tier diagnostic test. Collectively, the findings of these pioneering studies suggest a role for genetic testing and genetic counselling in the contemporary management of schizophrenia.
49

Genomic Characterization of Pleural Solitary Fibrous Tumours

Allo, Ghassan 11 July 2013 (has links)
Pleural solitary fibrous tumours (pSFTs) are uncommon soft tissue tumours of the pleura. that may recur and contribute to the patients’ demise. We analyzed a group of benign and malignant pSFTs for copy number alterations and for common mutations in oncogenes and tumour-suppressor genes. Malignant SFTs demonstrated more copy number alterations, especially 8q (c-myc) gain, 10q (include PTEN) loss, and 13q (Rb1) loss. Mutations were rare in this limited study.
50

Genomic Characterization of Pleural Solitary Fibrous Tumours

Allo, Ghassan 11 July 2013 (has links)
Pleural solitary fibrous tumours (pSFTs) are uncommon soft tissue tumours of the pleura. that may recur and contribute to the patients’ demise. We analyzed a group of benign and malignant pSFTs for copy number alterations and for common mutations in oncogenes and tumour-suppressor genes. Malignant SFTs demonstrated more copy number alterations, especially 8q (c-myc) gain, 10q (include PTEN) loss, and 13q (Rb1) loss. Mutations were rare in this limited study.

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